Just beginning to get some photos with the M-P ... And I really, really like it.
The raw and JPEG files that the M-P produces, when set to its defaults, are very different from what came out of the M9. The M-P files show more dynamic range, more resolution, less moire problems, and a flatter, more even/accurate color rendering. The Auto White Balance is shockingly better than the M9. The feel of the shutter, the speed with which it writes files, the new controls ... everything about the M-P feels an upgrade and an improvement over the M9.
I have found NOTHING to complain about or wish that I'd kept the M9. For me, the out of camera JPEGs with the M9 were useless, I turned them off, and every exposure needed to be white-balanced properly and adjusted to produce what I had in mind. I find that the amount of adjustment needed for the M-P is far less, and I have much more adjustment range to work with as well.
I'm sure others will differ with my opinion. That's fine with me. There are many excellent cameras on the market that are different in what they produce. If you like what the M9 does more than the M typ 240, enjoy it.